Thursday, June 17, 2010

So the last things to do are make the sponsons, assemble, paint and finish the toy. (And play with it before I have to give it away.) All in all, not so bad and not too many surprises ahead.

The sponsons on the sides are a defining feature of British WW1 tanks. I want them to move but still be sturdy. It would be nice to have the gun barrels move left and right as well as up and down, but at this scale they would have been a little fragile and probably a bit droopy. So a few doodles and a test cut or two later a pretty simple solution came up.

I took another piece of 2x3 and drilled a 3/4" hole through it with a spade bit. Then I took a 3/4" piece of dowel and set it down into a "V" made out of... you'll never guess... the little support corners from a clementine box! (Clementine boxes really are the onions of the frugal toy making world.) I drilled a 1/4" hole about half way through that dowel and then inserted a piece of 1/4" dowel into it. (Don't glue it into place yet though. If you do, you won't be able to make some of the cuts coming up.)

Drill all the way through and make sure you have a thick enough piece of scrap under it.

Simple jig that makes it easy to hold any size dowel in place. The triangles are glued down.

I cut the large dowel down to about 1 5/16" with the 1/4" hole being in the middle. I didn't want too tight of a fit because I want the gun to rotate without binding. With the barrel dowel in place I checked the fit and marked the widest point in the arc of the barrel rotation and then made straight cuts with the bandsaw. I tested the fit and made sure the larger dowel could rotate freely but not be pulled out to the front. Then I trimmed the sponson to the rough width and length.

I rotated the barrel through 90 degrees and marked where I need to make the cuts.

Here is the "rough cut" of the sponson along with the 1/8" plywood that will make the roof and floor.

I used clementine wood that had printing on it for the roof and floor. I just made the printing inward facing because often that paint will "bleed" through the acrylic craft paint I use to finish toys. (Note to self - look for non-toxic primer.) I have plenty of clear wood I could have used, but I wanted to leave a little proof on a hidden inside part of the tank that this had been built using food box wood. It might seem psycho, but I felt like it was a little "shout out" to Homer McNeil and his toys.

Use enough glue to get a solid seal all the way around. Use clamps and be sure not to get any glue on the dowel that holds the barrel. It needs to be able to rotate freely.

Don't glue the barrel in until after the top and bottom have dried and you have finished shaping the sponson.

I used a combination of the bandsaw and belt sander to get the final shape I wanted. There was a wide range in the shapes of the sponsons on the British tanks depending on the model number and the number of guns it carried. The next one I build might have a smaller dowel and barrel towards the back to house a machine gun. Anyway, mine doesn't match an exact version, but it captures the general idea.

Obviously, you'll need to make two sponsons. Make sure that your cuts and sanding match up. Now you can glue the barrels in.

Here we go, the home stretch. I painted it olive drab with the red and white recognition stripes at the front.I glued and clamped the sponsons one at a time so that I could be sure to line them up how I wanted them.I did change the location of the nylon clacker to the back of the tank and held it in with a small brass screw. It sounds better clacking "in" rather than out on the gear and it looks like it will be less wear on it. (Actually, I'm gonna keep an eye on it to see if it holds up. I might experiment with a thin metal one instead.)

A scornful look from a black cat isn't required at this stage, but it seemed to be help.

The infamous "clacker" in place. Cut from a surplus nylon Venetian blind slat.

The large letter/number combinations at the front of the hull were unit identifications in WW1. The smaller numbers at the back were tank serial numbers. I personalized the tank for my friend's kid by making his birthday the serial number and used a play on his name for the unit ID. I painted the letters and numbers using a very fine point brush and... yes... a toothpick.

The tops of the tracks are painted grey.

I did add small driver shields and painted small slots on them.

The last thing I fixed was the machine gun. I really didn't like how the 3/16" dowel looked. To fix it I drilled a 1/16" hole in the center of it and then expanded that hole with a 1/8" hole (doing it like that prevented splintering) and then put a piece of 1/8" dowel into that hole.

After the painting was done, I gave it a coat of spray acrylic and then gave it a test run on the floor.

All in all, not so bad. Nothing too tricky (although there must be an easier way to make the clacker... just saying.) Without the paint, I think this could be knocked out over a weekend without any problem.

Here are the rough plans as a cutting guide. BE SURE TO SET THE IMAGE TO PRINT LANDSCAPE! The tank tracks should be a little over 8" from tip to tip. I tapered the back of my sponsons but like I said, I might add smaller guns at the rear on the next one. (And there definitely will be a next one.)

Friday, June 4, 2010

I want the tank to make a noise as it is pushed. This is the "clacker" idea I mentioned earlier. Looking at other toys and thinking about cardboard in my bicycle spokes (I never would have ruined a real football card) I knew I needed to make a geared wheel with something flexible that intersected it at a right angle. As the wheel turns, that flexible something would make a clicking noise with each tooth on the wheel as it passed.

I used a 1 1/4" hole saw on a 1/2" piece of oak. (What? Toy Making Dad using using real wood? Scandal! -I know, but in fairness, it was a piece of scrap and this part really needs to be made out of hardwood.) This fit perfectly in the space I had on the axle between the other two wheels.

I used to have a job where one of the "guiding principles" was "Why make it simple, when you can make it complex?" With that, I present the 5 step program that takes about 4 times as long to type as it does just to make the silly geared wheel:

Take a 1 1/8" in diameter by 1/2" thick wheel with a 1/4" axle hole and place it over a drawing of a five pointed star and mark the points of the star on the wheel.

Give the wheel a turn so that those marks were now in the valleys of the star points, and then mark the points again.

Draw an interior circle on the wheel at the depth you want each gear gear to be.

Draw "v"s down from one point to the interior circle and then up to the next point for all ten marks.

Carefully use a band saw or a coping saw to cut out the gear.

If you use the band saw, make a simple jig with a 1/4" dowel sticking up out of a board. Then set the wheel down flat with the dowel through the hole. Carefully complete the cuts by moving the jig into the saw and then pulling it back out, rotating the wheel to the next position and then repeating all the cuts until you are done.

This is what I ended up with. Pretty cool but still functional and sturdy. Since my wheels are inside the toy and I don't have a lot of extra room, I test fitted and assembled the wheels and axles before I glued the sides to the hull.

The 4,865th test fitting

Mmmmmm, glue sandwich...

I tested the clacker with a small piece of vinyl and I got the sound I was looking for. I won't mount the vinyl until the very end though. I glued and clamped the center hull to one side of the tracks and let it cure overnight. I painted the inside areas that I would not be able to get at once the tank was assembled. (I also gave that area a quick spray acrylic seal.) Then I put in the axles and glued and clamped the other track side to the hull.

I wouldn't be able to paint inside the wheelwells if I waited until the tank was done.

Clamped up and curing. I tested the alignment several times to be sure the tank rolled evenly.

In researching British tanks in WW1 there seems to be some real question as to exactly what color they were. Most of the museum examples around the world have them in either an olive green or a darkish brown. The brown is pretty classy honestly, and my next one will be that color but I went with the olive green for this one. Mainly because that is what I saw in my mind when I first started thinking about how to build this.

I did add white and red recognition stripes to the front of the tank because they were used in WW1 and on British armor up through the early part of WW2. While not to scale... they seem to class it up a bit. I used regular masking tape. (I would have used the blue painters tape... IF I COULD HAVE FOUND IT!!!)

So, all we have left are the sponsons with cannons and final assembly and painting.(If you just can't wait... you can see the completed sponsons in the background of the picture above.)